Secondary electric clock



T. S. CASN ER.

SECONDARY ELECTRIC CLOCK.

APPLICATION FILED-APR. 19, 1921.

1,388,512, Patented Aug. 23, 1921.

PATENT OFFICE.

TEADDEUS STEPHENS CASNER, OF PLAINFIELD, NEW JERSEY.

SECONDARY ELECTRIC CLOCK.-

Specification of Letters Patent. Patent d A g; 2.3 1921 Application filed April 19, 1921. SerialNo. 462,659.

To all whom it may concern:

Be it known that I, THADDEUS STEPHENS CASNER, a citizen of the United States, and resident of Plainfield, county of Union, State of New Jersey, have invented certain new and useful Improvements in Secondary Electric Clocks, of which the following is a specification.

The present invention relates to secondary electric clocks.

The object of the invention is to provide a secondary clock in which all gearing, except the usual reducing gearing between the hand shafts, is eliminated, thereby greatly reducing in number the requisite moving parts, so that the clock is easy. to construct and assemble, may be quieklyrepaired, and may be made small in size, while at the same time it is positive and accurate in operation.

The inventibn may be embodied in different forms and one form is, by way of example, illustrated in the accompanying drawings and described in this specification.

In the drawings: I

Figure 1 is a side elevation of the clock, the casing and dial not being shown;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 shows a front View of a portion of the mechanism on a much larger scale.

The frame of the clock comprises essentially two plates 10 and 11 secured in fixed spaced relation, the rear plate 10 having rearwardly extending flanges 12 and 13 which support between them the electromagnet 14 and its pole pieces, the magnet being connected in circuit with a master clock and plate 10 is the minute shaft 16, the minute shaft and hour sleeve being connected by the usual reducing gearing R. Hour and minute hands H and M are supported respectively on the outer ends of the hour sleeve and minute shaft, and the inner end of the minute shaft has fixed thereon the disk shaped armature 17 which is of soft iron, and has sixty teeth of equal size and similar shape formed on its periphery. The pole pieces 18 and 1 9 of the electromagnet project through the plate 10 and have their forward ends adjacent the periphery of the armature 17, the ends of the pole pieces being formed with relatively narrow portions 20 facing toward the armature, the faces 21 of which are inclined to a plane passing through the axis of the minute shaft and through the pole pieces, that is, inclined to a tangent to the armature diskat the pole piece. One edge 22 of the portion 20, therefore, lies closer to the path of travel of the teeth of armature 17 than does the other edge 23. In Fig. 3 the path of travel of the tips of the teeth is indicated by the dotted line 24 audit will be seen that the tip of any. one tooth is much closer to the pole plece of the magnet when opposite edge 22 than when opposite any other point thereof.

A disk or roller 25 of insulating-material such as hard rubber is mounted upon a leaf spring 26 and normally pressed downwardly thereby into the recess between two adj acent teeth, as shown in solid lines in'Fig. 3 to hold the armature against rotation. When the electromagnet is energized, as it will be at mlnute intervals where there are sixt'y teeth on armature 17, the armature will be moved from the full line to the dotted line position (Fig; 3) so that the tips of teeth 27 which formerly lay opposite edges 23 lie opposite edges 22 as the armature moves into a position which enables the flux to pass across the smallest possible air space. In this movement the roller 25 is raised against the action of spring 26 from its full line to dotted line position (Fig. 3) in which latter position it is resting on the point of one of the teeth. When the magnet 14 is deenergized, the spring 26 acts to move roller 25 downwardly and to continue the movement of the armature until the roller again contacts with two adjacent teeth and can move downwardly no longer. The armature will now occupy the position indicated in full lines in Fig. 3 and the electromagnet may be again energized at the termination of another minute to advance the same another tooth, and thereby advance the hands. I I

It is apparent that the number of moving parts of the clock have been reduced to the minimum and all gearing eliminated exce t the reducing gearing between the hand sha s which can not be dispensed with in any case in which two hands are employed. The individual parts of the mechanism are of great simplicity, easily fabricated, and are durable. No springs except leaf spring 26 are employed, and no weights. The absence of gearing renders the usual spring clutch placed between the minute shaft and the clock gearing unnecessary, and to set the clock it is only necessary to move the hands, the armature 17 rotating idly.

lVhat is claimed is:

1. In a secondary electric clock, in combination, a wheel having peripheral projections constituting an armfature, an electromagnet associated with the wheel and adapted to attract said projections successively as successive impulses pass through the magnet, and a detent for holding the wheel between impulses. i

2. In a secondary electric clock, in combination, a. wheel having peripheral projections constituting an armature, an electromagnet associated with the wheel and adapted to attract said projections successively as successive impulses pass through the magnet, and a detent for holding the wheel between impulses, said detent being adapted to position the teeth or projections in operative relation to the electromagnet.

3. In a secondary clock, in combination, a wheel having a plurality of peripheral projections spaced at equal intervals around its periphery, an electro magnet positioned with its pole piece in the plane of the wheel and adjacent the periphery thereof to attract said projections successively as successive impulses iass through the magnet, and a detent for holding the wheel between impulses.

4. In a secondary clock, in combination, a wheel havinga plurality of peripheral projections spaced at equal intervals around its periphery, an electro-magnet positioned with its pole piece in the plane of the wheel and adjacent the periphery thereof the width of the pole piece being greater than half the distance between two successive teeth of the wheel, to attract said projections successively as successive impulses pass through the magnet, anda detent for holding the wheel between impulses.

5. In a secondary clock, in combination, a wheel, having a plurality of peripheral projections spaced at equal intervals around its periphery, an electro-magnet positioned with its pole piece in theplane of the wheel and adjacent the periphery thereof to attract said projections successively as successive impulses pass through the magnet, the face of:

the pole piece toward the wheel being in a plane inclined to a tangent to the wheel at the pole piece, and a detent for holding the wheel between impulses.

6. In a device of the class described, in combination. a revoluble'member constitutmg an armature and having a series of projections arranged along a circular are, an electro-magnet associated with said member and adapted to attract said projections succes'sively as successive impulses pass through the magnet, and means for holding the member stationary when the electromagnet is deenergized,

7. In a device of the class described, in combination, a revoluble member constituting an armature and having a series of projections arranged along a circular arc, an electromagnet associated with said member and adapted to attract said projections successively as successive impulses pass through the magnet, and means adapted to become active when the electromagnet is de'e'nergized to position a protection in operative relationship to the electromagnet.

8. In a device of the class described, in combination, a revoluble member constituting an armature and having a series of projections arranged along a circular arc, an electromagnet associated with said member and adapted to attract said projections successively as successive impulses pass through the magnet, and a roller normally pressed into the space between two projections of the revolublemember, for positioning said member with a projection in operative relationship to the electromagnet.

9. In a device of the class described, in combination, a revoluble member constituting an armature and having a series of projections arranged along a circular are, an electromagnet associated with said member and adapted to attract said projections successively as successive impulses pass through the magnet, a roller adapted to enter the space between two projections of the revoluble member and to engage both of said proj ections, and spring means normally pressing said roller toward said member to position said member with a projection in operative relationship to the electromagnet.

10. In a device of the classdescribed, in combination, a revoluble member constituting an armature and having a series of projections arranged along a circular arc, an electromagnet associated with said member and having a lurality of pole pieces each of which is a apted to attract said projec tions successively as successive impulses pass through the magnet, and means adapted'to become active when the electromagnet is deenergized to osition a projection in operative relationship to each pole piece of the electromagnet.- I

In testimony whereof I hereunto afiix my signature.

THADDEUS STEPHENS CASNER. 

